1. Field of the Invention
The present invention generally relates to card type wireless communication modules. More specifically, the present invention relates to a card type wireless communication module including a high frequency terminal where a plating process is applied.
2. Description of the Related Art
In a mobile communication terminal such as a portable phone, it is generalized that the terminal has a wireless function such as infrared or Bluetooth (registered trademark) transmitting and receiving for transferring data a short distance. In addition, it has been demanded that a function of a wireless LAN for transferring data an intermediate distance be additionally provided in the mobile communication terminal.
The wireless LAN is additionally provided, for example, in the following way. That is, a circuit block of the wireless LAN including an antenna is provided at a card device such as a micro SD card so that a card type wireless communication module is formed. This card type wireless communication module is provided at a mobile communication terminal. In addition, the following technique is known (see, for example, Japanese Laid-Open Patent Application Publication No. 2009-60160). That is, a card device antenna is provided at the mobile communication terminal. When the card type wireless module is provided at the mobile communication terminal, the card device antenna is connected to the card device.
Since this kind of card type wireless communication module is a card, an inserting and pulling out process is performed with a corresponding connector many times. Because of this, it is required that an electric resistance of a terminal provided at the card type wireless communication module be low. In addition, in a case where an oxide film is formed on a surface of the terminal, since the oxide film normally has insulating properties, the electric resistance is increased. Accordingly, it is desirable that the terminal provided at the card type communication module be made of a non-oxidizing material. Therefore, it is normal practice that an electrolytic plating process is applied to the terminal provided at the card type communication module.
In order to apply gold plating to the terminal of the card type communication module, it is necessary to apply a voltage to each of the terminals. Therefore, it is necessary to provide a copper foil pattern (feeding wiring pattern) for electrolytic plating at each of the terminals separated from a signal line or an electric power line of the terminal.
FIG. 1 is a schematic view showing an internal structure of a related art card type wireless communication module. More specifically, FIG. 1 shows a board 300 of a related art card type wireless communication module 200 where feeding wiring patterns 290 are provided. As illustrated in FIG. 1, plural feeding wiring patterns 290 connected to corresponding terminals 210, 260, and 270 one by one are formed in a feeding wiring pattern arrangement area 330 on the board 300. An antenna 230 is provided in a position lower than the feeding wiring pattern arrangement area 330 of the board 300.
The feeding wiring pattern 290 is not necessary after a plating process performed on the terminals 210, 260 and 270 is completed. If the feeding wiring pattern 290 still remains, the terminals 210, 260 and 270 may be shorted. Because of this, in the related art, after the plating process is completed, a process for cutting each of the feeding wiring patterns 290 is performed (see, for example, Japanese Laid-Open Patent Application Publication No. 2009-123958 and Japanese Laid-Open Patent Application Publication No. 2008-192993).
FIG. 2 is a schematic view of the related art card type wireless communication module 200 illustrated in FIG. 1 where the feeding wiring patterns 290 are cut. Positions indicated by arrows X in FIG. 2 are cutting positions of the feeding wiring patterns 290.
However, in the related art, parts of the feeding wiring patterns 290 are cut so that connections between the feeding wiring patterns 290 and the corresponding terminals 210, 260 and 260 are cut. Therefore, the parts of the feeding wiring patterns 290 remain on the board 300 after the cutting process is completed. The remaining feeding wiring patterns 290 are called a remaining wiring pattern 290a. 
In the meantime, if a conductive line is provided in parallel with a high frequency transmission line, an open stub is created so that impedance of the transmission line may be influenced. Therefore, if the remaining wiring pattern 290a is provided in parallel with the high frequency transmission line, mismatch of impedance may be generated on the transmission line. Because of this, elements reacting at a high frequency may be increased so that transmission loss may be generated.
Furthermore, in a case where the remaining wiring pattern 290a has a length (for example, ½ wavelength or ¼ wavelength) whereby there is resonance relative to a high frequency signal to be transmitted, the remaining wiring pattern 290a may operate as an antenna and thereby high frequency electric energy may be unintentionally radiated.
In addition, in the related art, a single feeding wiring pattern 290 is provided to a single terminal 210. Accordingly, it may be necessary to provide a large number of feeding wiring patterns 290. Therefore, the feeding wiring pattern arrangement area 330 on the board 300 may be wide.
Since the communication module 200 is a thin card type module, the mechanical strength of the communication module 200 may be low. Accordingly, it may be preferable to form a reinforcing pattern at the board 300. However, if an area of the feeding wiring pattern arrangement area 330 is wide, there is no freedom degree of design for the board 300 and therefore it may not be possible to form the reinforcing pattern.